Synergy between interleukin 4 and interleukin 2 conveys resistance to cyclosporin A during primary in vitro activation of murine CD8 cytotoxic T cell precursors

Even though cyclosporin A (CsA) suppresses in vitro production of lymphokines such as interleukin 2 (IL 2) and responsiveness of cytotoxic T cell (CTL) precursors to IL 2, thereby inhibiting the in vitro generation of CTL, in vivo CsA does not affect the induction of alloreactive CTL. This paradox suggests that CsA-resistant signals are operating in vivo. Using an in vitro model system in which the requirement for antigen-presenting cells during primary activation of resting murine CD8 T cells is bypassed by immobilized anti-CD3 monoclonal antibodies, we here describe conditions in which IL 4 conveys CsA resistance to murine CD8 T cells triggered by immobilized anti-CD3 monoclonal antibodies to respond to IL 2. CsA resistance of IL 4 and IL 2-responsive CD8 T cell parallels conditions in which signals provided by IL 4 and IL 2 synergize with each other. CsA dissociates in vitro proliferative and differentiative events by suppressing the former while enhancing the latter. In addition to the known pleiotropic effects of IL 4, our results define an IL 4-dependent, CsA-resistant signal pathway which allows CTL differentiation in the absence of significant cell proliferation.

Role of commissural projections in the representation of bilateral auditory space in the barn owl's inferior colliculus

The central nucleus of the barn owl's inferior colliculus (ICc) contains a representation of both the ipsilateral and contralateral auditory hemifields. The representation of ipsilateral space is found in the "core" of the ICc, a subdivision defined by the terminal field of nucleus laminaris, the avian analogue of the medial superior olivary nucleus. The representation of contralateral space is found in the lateral portion of the "shell" of the ICc. The shell surrounds the core and is defined by the terminal field of the nucleus angularis, one of the cochlear nuclei. The representation of ipsilateral space in the core of the ICc may be accounted for by the crossed projection from the nucleus laminaris because most of the nucleus laminaris is devoted to a representation of contralateral space. We present evidence to suggest that the representation of contralateral space is due to a commissural projection from the core of one side to the lateral shell of the opposite side. Injection of horseradish peroxidase (HRP) into the lateral portion of the ICc shell produced retrogradely labeled somata in the core of the opposite side. Injection of tritiated proline into the core produced anterograde label confined to the lateral shell, thus confirming the observations made with HRP. Thus, for example, the left ICc core, which contains predominantly a representation of the left hemifield, innervates the right lateral shell, endowing it with a representation of the left, or contralateral hemifield. The representation of contralateral space in the lateral shell is ultimately conveyed to the external nucleus of the inferior colliculus where it contributes the horizontal axis to a two-dimensional map of space.

[Frequency of colonization and pneumonia and development of resistance in long-term ventilated intensive-care patients subjected to selective decontamination of the digestive tract]

Colonization of the oropharynx with potentially pathogenic microorganisms (PPM) is a highly significant factor in the pathogenesis of bacterial pneumonia in intensive care patients. Via colonization of the oropharynx, bacteria pass into the tracheobronchial tree, where they can give rise to pneumonia after overcoming pulmonary resistance mechanisms. By a new, prophylactic antibiotic treatment schedule consisting in selective decontamination of the digestive tract (SDD) with locally applied nonabsorbable antibiotics, Stoutenbeek achieved drastic lowering of the colonization and infection rate in trauma patients. In the present study, we wanted to check whether this new prophylactic antibiotic schedule can be applied on a surgical intensive care ward in all patients with long-term ventilation, irrespective of the diagnosis, and whether it affords advantages over a conventional antibiotic schedule. MATERIALS AND METHODS. All patients on a surgical intensive care ward in whom it was expected that mechanical ventilation would be necessary for more than 4 days were included in the study. During the first 6 months 83 patients were investigated, in whom antibiotics were only administered when the presence of infection had been confirmed, in accordance with generally accepted guidelines (control group). In the second 6-month period, 82 patients were selectively decontaminated with 4 x 100 mg polymyxin E, 4 x 80 mg tobramycin and 4 x 500 mg amphotericin B, administered through the gastric tube and in an antimicrobial paste in the oropharynx (SDD group). The SDD schedule entailed systemic administration of cefotaxime in the first 3-4 days. RESULTS. In the control group, enterobacteria/Pseudomonas spp. were isolated significantly more frequently than in the SDD group (P less than 0.001): in the pharyngeal smear in up to 53%, in the tracheal secretion up to 36%, and in the rectal smear in up to 93% of the patients In the SDD group in the 1 week the frequency of gram-negative aerobic bacteria in the pharynx decreased from 33% to 5%, in the tracheal secretion from 23% to 14% and in the rectum from 86% to 52% (24% in the second week). However, the decrease in gram-negative microorganisms was accompanied by significant increase in the frequency of Staphylococcus epidermidis and enterococci. The SDD schedule proved to be effective with regard to the rate of infection. In the control group, 35 patients developed pneumonia (42%) as against 5 patients receiving SDD prophylaxis (6%). The duration of mechanical ventilation in the patients with pneumonia was 5 days longer than in patients without pneumonia.(ABSTRACT TRUNCATED AT 400 WORDS)

Free flow electrophoresis as a method for the purification of enzymes from E. coli cell extract

The application of the four techniques of free flow electrophoresis (zone electrophoresis, isotachophoresis, isoelectric focusing and field step electrophoresis) for the purification of proteins from a complex protein mixture was investigated. For this purpose alpha-amylase (EC 3.2.1.1) from Aspergillus oryzae was added and reisolated from E. coli cell extract. The chosen enzyme and the biological extract are models for many industrial separation problems. In optimized experiments purity, purification factor, yield, throughput and efficiency were calculated. The best results were obtained with field step electrophoresis in combination with zone electrophoresis. High purity (0.82 mg enzyme/mg total protein) and high throughput (111 mL sample/h) were achieved using this technique. Field step electrophoresis gave the best throughput (330 mL sample/h), but low purity (0.63 mg enzyme/mg total protein). This technique can also be used for a simple concentration of the sample. With zone electrophoresis a purity of more than 0.95 mg enzyme/mg total protein was obtained, which was the best of all techniques. However, the enzyme concentration was decreased due to dilution with buffer solution after the separation. Isotachophoresis was the most difficult technique, combined with a relatively low recovery of 31% of the enzyme activity. In a purification scheme, free flow electrophoresis is able to substitute one or even several chromatography steps with a negligible loss of biological activity.

A previously unrecognized large fraction of cytotoxic lymphocyte precursors is present in CD4+ human peripheral blood T cells

We describe a limiting dilution (LD) culture system in which cell sorter-purified CD4+ (and CD8+) peripheral blood T cells are cocultured with irradiated, anti-CD3 mab-producing OKT3 hybridoma cells. Under these conditions, one out of 2-3 CD4+ (and CD8+) T cells is induced to clonal proliferation. In striking contrast to previously described LD culture systems, every growing CD4+ cell clone displayed cytotoxic activity when tested in a lectin-facilitated 51Cr release assay against P815 target cells. This contrasts with the development of cytotoxic CD4+ T cells in alloantigen-stimulated LD cultures, where only one out of 15-20 proliferating CD4+ cells killed P815 in the presence of PHA, and one out of 300-500 proliferating CD4+ cells displayed alloantigen-specific cytotoxic activity. Furthermore, we have established antigen-specific proliferating CD4+ T cell clones which do not exert antigen-specific cytotoxicity but can be cytotoxic when crosslinked to target cells via lectin or monoclonal antibody (anti-CD3, anti-TCR). Our results show that a previously unrecognized large fraction (at least 30-50%) of all peripheral blood CD4+ T cells can give rise to cytotoxic effector cells. The mode of CD4+ T cell activation (OKT3 hybridoma versus alloantigen) thus determines whether the intrinsic cytotoxic capacity of CD4+ T cells is functionally activated or not.

[Description and assessment of a rapid new method for measuring erythrocyte sedimentation rate]

A new method for the rapid photometric determination of the erythrocyte sedimentation rate (ESR) is described and compared with the Westergren technique. The basis of this method is the development of a new physical equation valid for transport processes, in which sedimentation processes can be described by means of a linear regression analysis. After the mathematical transformation, the measured ESR data follow a linear function. The apparatus evaluated measures within a few minutes the velocity profile of the ESR over a distance of about 2 X 10(-4) meter by kinetic determination of the optical density of a short blood column filled in a small cuvette. A microprocessor calculates the linear regression and derives the one and two hour values by extrapolation. The correlation of this method with the standard Westergren technique, determined over 20 days is acceptable (R = 0.95; n = 368). The reproducibility of the same sample (n = 20) is better than that of the conventional procedure. The reproducibility determined with different instruments (n = 20) is comparable to the precision of the Westergren method. The practical value of this new time- and blood-saving, well standardized method for an efficient patient-care is discussed.

Adoptive transfer of human peripheral blood lymphocytes (PBL) in scid mice

Two protocols were examined for the ability to transfer a human T cell system into SCID mice. Upon intraperitoneal injection (i.p.) of human peripheral blood lymphocytes (PBL) into SCID mice the injected cells could be recovered over weeks from the peritoneal cavity, yet human T cells did not seed into secondary lymphoid organs such as the spleen, lymph nodes or bone marrow. In contrast, SCID mice grafted with human embryonal thymus tissue contained high numbers of CD4+CD8- and CD8+CD4- human T cells in their lymph nodes and spleen when they had been injected i.p. with human PBL.

Osteopetrosis: report of a case and discussion of the differential diagnosis

A case of autosomal dominantly inherited osteopetrosis is presented, together with a discussion of the features of this disease and the major diseases to be considered in the differential diagnosis.

Anti-asthmatic effects of onions. Alk(en)ylsulfinothioic acid alk(en)yl-esters inhibit histamine release, leukotriene and thromboxane biosynthesis in vitro and counteract PAF and allergen-induced bronchial obstruction in vivo

Five alk(en)ylsulfinothioic acid alk(en)yl-esters isolated from onions and four synthetic thiosulfinates inhibited 5-lipoxygenase of porcine leucocytes, histamine release and leukotriene B4 and C4 biosynthesis of human polymorphonuclear leucocytes, thromboxane B2 biosynthesis by human platelets and allergen- and PAF-induced bronchial obstruction of guinea-pigs. The anti-asthmatic and anti-inflammatory effects of onions depend in part on the thiosulfinate moiety: (Formula: see text).

TLC and HPLC analysis of Echinacea pallida and E. angustifolia roots

The roots of ECHINACEA PALLIDA are characterized by TLC and HPLC fingerprints of the polyacetylenes, polyenes, and the caffeic acid derivatives. The fingerprints can also be used for the differentiation between E. PALLIDA and E. ANGUSTIFOLIA root extracts. The main constituents of E. PALLIDA roots are tetradeca-8 Z-ene-11,13-diyn-2-one ( 2), pentadeca-8 Z-ene-11,13-diyn-2-one ( 3), pentadeca-8 Z,13 Z-dien-11-yn-2-one ( 4), pentadeca-8 Z,11 Z,13 E-trien-2-one ( 5), pentadeca-8 Z,11 E,13 Z-trien-2-one ( 6), pentadeca-8 Z,11 Z-dien-2-one ( 7), and echinacoside ( 13). E. ANGUSTIFOLIA is usually void of these polyacetylenes and polyenes and is characterized by isobutylamides, echinacoside, and cynarine. The polyacetylenes of E. PALLIDA are very susceptible to autoxidation to the 8-hydroxy-9-ene derivatives. Thus, the chemical composition of the roots depends on the storage conditions.

IL-4 bypasses the immune suppressive effect of cyclosporin A during the in vitro induction of murine cytotoxic T lymphocytes

We have analyzed at the clonal level the effect of IL-4 on the immune suppressive action of cyclosporin A (CsA) during the in vitro primary activation of anti-MHC alloantigen-reactive murine CD8+ CTL. Although neither IL-4 nor IL-2 alone were able to overcome the CsA-mediated suppression, the addition of IL-4 in the presence of IL-2 restored in a dose-dependent manner the induction of cytolytic activity. On the other hand, CsA greatly impaired proliferative responses of alloantigen-reactive CD8 T cells, thereby operationally dissecting proliferative responsiveness from acquisition of cytolytic activity during primary activation of alloantigen-reactive CD8+ T cells. The existence of a CsA-resistant induction pathway for Ag-specific CD8+ T cell-mediated cytolytic activity may be of relevance for experimental and clinical organ transplantation.

IL-4 bypasses the immune suppressive effect of cyclosporin A during the in vitro induction of murine cytotoxic T lymphocytes

We have analyzed at the clonal level the effect of IL-4 on the immune suppressive action of cyclosporin A (CsA) during the in vitro primary activation of anti-MHC alloantigen-reactive murine CD8+ CTL. Although neither IL-4 nor IL-2 alone were able to overcome the CsA-mediated suppression, the addition of IL-4 in the presence of IL-2 restored in a dose-dependent manner the induction of cytolytic activity. On the other hand, CsA greatly impaired proliferative responses of alloantigen-reactive CD8 T cells, thereby operationally dissecting proliferative responsiveness from acquisition of cytolytic activity during primary activation of alloantigen-reactive CD8+ T cells. The existence of a CsA-resistant induction pathway for Ag-specific CD8+ T cell-mediated cytolytic activity may be of relevance for experimental and clinical organ transplantation.

Quantitative assessment of interleukin-2-producing alloreactive human T cells by limiting dilution analysis

A limiting dilution (LD) culture system was developed to estimate the frequency of IL-2 producing alloantigen-reactive human helper T lymphocytes (HTL). E rosette-purified T cells or cell sorter-separated CD4+ and CD8+ subsets were co-cultured under LD conditions with irradiated allogeneic Epstein-Barr virus-transformed lymphoblastoid cell lines (LCL) in the absence of additional growth factors. IL-2 in microculture supernatants was detected in a bioassay combined with rapid colorimetric visualization (cleavage of MTT). Under these conditions, one out of 250-800 E+, 180-280 CD4+, and 440-1000 CD8+ T cells produced IL-2 after a culture period of 3 days. This quantitative analysis of alloantigen-specific human HTL is complete within 4 days and thus provides a rapid method with potential applications in various clinical situations, e.g., transplantation medicine.

Cross-linking of T-cell receptors is insufficient to induce IL-2 responsiveness (activation) in resting Lyt-2+ T cells. IL-4 or RIF are essential as second signal

High-density (resting) murine Lyt-2+ T cells exposed in vitro to the ligand concanavalin A (Con A), or immobilized F23.1 monoclonal antibody (mAb) recognizing an allotypic determinant on the T-cell receptor (TCR), or high-density (resting) allogeneic B stimulator cells remain IL-2-unresponsive; such cells do not express functional IL-2 receptors unless reconstituted with accessory cells. We conclude that cross-linking of TCR is insufficient as signal to induce IL-2 responsiveness, that is, activation. Both the macrophage product RIF and the T-cell product interleukin-4 efficiently induce the IL-2 responsiveness in resting Lyt-2+ T cells exposed in vitro either to the ligand Con A, or to immobilized F23 mAb, or to nonimmunogenic allogeneic stimulator cells. We conclude that two restricting points control the induction of IL-2 responsiveness (activation) in antigen-driven Lyt-2+ T-cell responses, that is, cross-linking of TCR by way of presented antigen and "costimulator" activity expressed by accessory cells. Both RIF and IL-4 express costimulator activity, therefore replacing the requirement for accessory cells.